Water heater

ABSTRACT

A water heater including a furnace having a plurality of horizontally disposed tubes forming a water tube boiler disposed therein; a vertically disposed preheater is connected to the boiler, and flow control valves are connected to the preheater; the boiler, preheater and flow control valves being constructed and arranged as a unit, slidably mounted on a track secured within the furnace housing, whereby the unit may be removed from the furnace through the furnace access door to facilitate the maintenance of the unit.

United States Patent [191 Johnson WATER HEATER [76] Inventor: Clarence S. Johnson, PO. Box 940,

Pomona, Calif. 91769 [22] Filed: Oct. 14, 1971 [21] Appl. No.: 189,205

[52] U.S. Cl. 122/367 C, 122/406, 122/DlG. 11

[51] Int. Cl. F22b 37/10 [58] Field of Search l22/D1G. 11, 250, 122/367 C, 406; 165/78 [56] References Cited UNITED STATES PATENTS 3,292,598 12/1966 Miller et al. 122/406 2,256,882 9/1941 Sebald 165/78 X 2,615,687 10/1952 Simmons 165/78 2,625,915 1/1953 Glasgow et a1.

l22/DlG. 1 1

[ June 26, 1973 3,282,257 11/1966 Mclnerney et al 122/250 Primary Examiner-Kenneth W. Sprague Attorney-Rupert J. Brady, James G. OBoyle et a1.

[57] ABSTRACT A water heater including a furnace having a plurality of horizontally disposed tubes forming a water tube boiler disposed therein; a vertically disposed preheater is connected to the boiler, and flow control valves are connected to the preheater; the boiler, preheater and flow control valves being constructed and arranged as a unit, slidably mounted on a track secured within the furnace housing, whereby the unit may be removed from the furnace through the furnace access door to facilitate the maintenance of the unit.

4 Claims, 4 Drawing Figures PAIENIEDJUNZB ma 3.141.169

SHEEI 1 0F 3 INVENTOR CLARENCE s. JOHNSON 0 a gv fvw ATTORNEYS WATER HEATER CROSS-REFERENCE TO RELATED APPLICATIONS:

The temperature responsive valve assembly employed in the heater of the present invention is described and claimed in my copending application Ser. No. 150,080 filed June 4, 1971 entitled Temperature Responsive Valve Assembly", and the manner in which the boiler tubes are connected to the front and rear headers of the boiler is disclosed and claimed in my copending application Ser. No. 182,471 filed Sept. 21, 1971 entitled Boiler Tube End Fittings.

BACKGROUND OF THE INVENTION The heater of the present invention is intented to be primarily used for heating water for a swimming pool. Various types of swimming pool water heaters have been proposed wherein the water is continuously circulated through the pool filter system, into the heater, and discharged into the pool from which it is eventually recirculated through the filter system once again. While these heaters have been satisfactory for their intended purpose, they, have been characterized by certain inherent disadvantages particularly with regard to the maintenance and repair of the heater. For instance, it has been found that the relatively cool water flowing into the boiler tubes forms condensation on the tube fins thus increasing the humidity within the furnace which results in the formation of scales and rust within the furnace resulting in the ultimate deterioration of the tubes and furnace walls. The construction of these heaters is such that they are either impossible to repair, thus requiring total replacement, or, if repairable, access to the damaged parts of the heater can'only be obtained after the expenditure of considerable time and effort in dismantling the heater.

After considerable research and experimentation, the heater of the present invention has been devised to overcome the disadvantages experienced in hitherto employed water heaters, and comprises essentially a plurality of spaced, parallel, horizontally disposed water tubes disposed in a furnace, a vertically disposed preheater communicating with the tubes and flow control valves connected to the preheater; the water tubes, preheater and flow control valves being connected together as a unit which is slidably mounted on a track secured within the furnace. By this construction and arrangement, the unit may be removed from the furnace through the furnace access door to facilitate the maintenance of the unit, and the preheating of the water before it flows into the water tubes, results in a considerable reduction of the humidity within the furnace thereby preventing the formation of scale and rust on the tube and furnace walls.

BRIEF DESCRIPTION OF THE DRAWINGS:

FlG. 1 is a fragmentary, perspective view of the heater assembly of the present invention;

FIG. 2 is a front elevational view, partly in section, of the preheater assembly and associated flow control valves;

FIG. 3 is a view taken along line 3-3 of FIG. 2; and

FIG. 4 is a view taken along line 4-4 of FIG. 3.

Referring to the drawings and more particularly to FIG. 1 thereof, the water heater of the present invention comprises a furnace 1 including a combustion chamber 2 having its four side walls lined with a suitable refractory material 3, the top wall 4 of the combustion chamber having a conventional flue pipe 5 extending therethrough. A pair of guide rails 6 extend from the front to the rear of the furnace and are secured to the top wall 4 of the furnace and support a pair of slide runners 7 secured to and extending between the front and rear headers of a water tube boiler 8. A preheater 9 is connected to and communicates with the boiler 8 and is bolted to a transversely extending bracket 10 secured to the side walls of the furnace. The preheater 9 is connected to an inlet pipe 11 and outlet pipe 12 through flanged connections 13 and 14, respectively, the inlet pipe communicating with a T- connection 15 having its opposite ends connected to a temperature responsive valve assembly 16 and a pressure regulating valve 17. The boiler 8, preheater 9 and control valves 16 and 17 are connected as a unit which is suspended from the slide rails 6 through slide runners 7. By this construction and arrangement when it is desired to gain access to the various components of the heater for maintenance or repair it is only necessary to disconnect the flange connections 13 and 14 and remove the bolts securing the preheater 9 to the bracket 10. The unit is then free to slide, by means of runners 7, outwardly of the furnace through the front access door.

The details of the preheater are illustrated in FIGS. 2 and 3 wherein it will be seen that the preheater comprises a vertically disposed cast housing 18 having top and bottom walls 19 and 20, side wall 21 and 22 and baffles 23, 24 and 25 extending inwardly of the housing from the side walls. A back wall 26 is integrally connected to the top, bottom and side walls and a front wall 27 (FIG. 3) is bolted to the housing walls and baffles as at 28. Each of the side walls 21 and 22 also being provided with a bracket 29 through which the preheater is bolted to the bracket 10 secured to the furnace. A serpentine conduit 30 is positioned within the housing and extends from an inlet fitting 31 to an outlet fitting 32 which communicates with the tubes of the boiler 8, to be described more fully hereinafter. An orifree 33 is formed in the back wall 26 of the housing and communicates with the boiler outlet, the bottom wall 20 of the housing having a port 34 formed therein communicating with an outlet fitting 35.

The temperature responsive valve assembly 16 and pressure regulating valve 17 are connected to the bottom wall of the housing and are adapted to control the volume of water supplied to the preheater and boiler. The details of the construction of the temperature responsive valve assembly 16 are disclosed in my aforementioned copending application Ser. No. 150,080 filed June 4, 1971, and the pressure regulating valve 17 is a conventional, diaphragm type valve, spring biased to closed position, and having an adjustable handle for varying the biasing force of the spring. The temperature sensing bulb for the thermal valve would be disposed in the preheater housing in proximity to the orifice 33 whereby the temperature of the water flowing from the boiler would be sensed to thereby actuate the valve 16 which, in turn, controls the volume of water flow through the boiler. The pressure regulating valve 17 forms a shunt valve designed to by-pass the volume of water flow not needed toisupply the demands of the thermal valve 17.

To complete the description of the preheater, the side wall 22 of the housing is provided with orifices or wells 36 to accommodate the thermal valve temperature sensing bulb, a high limit bulb and a fail-safe thermal unit, if employed, or a thermometer during calibration checks, and threaded bosses 37 and 38 are formed in the T-connection 15 and fitting 35, respectively, for accommodating upstream and downstream pressure gauges.

The details of construction of the boiler are shown in FIGS. 3 and 4 wherein it will be seen that a plurality of spaced, horizontally disposed, finned tubes 39 are mounted between the front and rear headers 40 and 41, respectively, each of the tubes being secured to. the boiler end plates by nut assemblies 42 of the type disclosed in my aforementioned patent application Ser. No. 182,471 filed Sept. 21, 1971 entitled Boiler Tube End Fittings. The front header 40 is connected to the preheater by pipe fittings 43 and 44 which communicate with the preheater outlet 32 and orifice 33, respectively, the front and rear headers being provided with baffles 45 to cause the water being heater to flow in a direction indicated by the arrows shown in FIG. 4.

The heater for the boiler consists of a suitable electric, gas or oil burner disposed within the furnace combustion chamber 2 below the tubes 39, whereby water to be heated is circulated through the preheater conduit 30 and enters the boiler inlet 43', the water being heated while circulating through the boiler tubes 39 to the boiler outlet 44. The heated water flows through the preheater housing as directed by the baffles 23, 24 and 25 to the preheater outlet port 34. It will thus be seen that the incoming water flowing through the preheater conduit 30 is heated by the water flowing from the boiler, it being contemplated that the temperature of the incoming water will I be increased by 20F to thereby raisethe temperature of the incoming water above its dew-point, thus preventing the formation of condensation on the boiler tubes. The pressure regulating valve 17 is adjusted to provide a heating range of 135 to 140F at the heater outlet 34, and the thermal valve 16 is calibrated to control the flow and temperature'of the water within this range.

it will be readily appreciated by those skilled in the art that the assembly of the present invention provides an improved heater wherein the incoming water is not only preheated to prevent the formation of condensation on the boiler tubes, thus reducing the formation of scales andrust within the furnace, but also the provision of the slide runners 7 employed for suspending the boiler 8, preheater 9 and control valves 16 and 17 as a unit on the slide rails 6 facilitates the access to the various components of the heater since the heater may be slid outwardly of the furnace through the furnace access door.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.

I claim:

1. A water heater comprising a furnace, a boiler mounted within said furnace, at preheater connected to said boiler, said preheater comprising a vertically disposed housing, a serpentine conduit disposed within said housing, a cold water inlet fitting connected to said housing one end of said conduit being connected to said inlet fitting, an outlet fitting connected to said housing, said outlet fitting communicating with the inlet to said boiler, the opposite end of said conduit being connected to said outlet fitting, the boiler outlet fitting communicating with the preheater housing, a hot water outlet fitting connected to the housing, and baffles mounted in said housing for directing hot water from the boiler around the serpentine conduit to the hot water outlet fitting, said boiler, preheater, control valve means and fittings being connected as a unit, and slide means connecting said unit to said furnace, whereby the unit may slide outwardly from the furnace to facilitate the maintenance of the unit.

2. A water heater according to claim 1 wherein the boiler comprises a plurality of spaced, parallel, horizontally disposed finned tubes connected at their ends to a front and rear header.

3. A water heater according to claim 1, wherein the valve control means comprises a temperature responsive valve assembly'having its outlet connected to the preheater inlet fitting, the water inlet pipe fitting'including a T-connection having one arm thereof connected to the inlet of the temperature responsive valve assembly, a pressure regulating valve, the opposite arm of said T-connection being connected to the inlet of said pressure regulating valve, the outlet of said pressure regulating valve communicating with the hot water outlet fitting on said preheater.

4. A water heater according to claim 2 wherein the slide means comprises a pair of slide runners secured to and extending between the front and rear headers of the boiler, and a pair of guide rails secured to the top wall of the furnace, said guide rails supporting said slide runners. 

1. A water heater comprising a furnace, a boiler mounted within said furnace, a preheater connected to said boiler, said preheater comprising a vertically disposed housing, a serpentine conduit disposed within said housing, a cold water inlet fitting connected to said housing one end of said conduit being connected to said inlet fitting, an outlet fitting connected to said housing, said outlet fitting communicating with the inlet to said boiler, the opposite end of said conduit being connected to said outlet fitting, the boiler outlet fitting communicating with the preheater housing, a hot water outlet fitting connected to the housing, and baffles mounted in said housing for directing hot water from the boiler around the serpentine conduit to the hot water outlet fitting, said boiler, preheater, control valve means and fittings being connected as a unit, and slide means connecting said unit to said furnace, whereby the unit may slide outwardly from the furnace to facilitate the maiNtenance of the unit.
 2. A water heater according to claim 1 wherein the boiler comprises a plurality of spaced, parallel, horizontally disposed finned tubes connected at their ends to a front and rear header.
 3. A water heater according to claim 1, wherein the valve control means comprises a temperature responsive valve assembly having its outlet connected to the preheater inlet fitting, the water inlet pipe fitting including a T-connection having one arm thereof connected to the inlet of the temperature responsive valve assembly, a pressure regulating valve, the opposite arm of said T-connection being connected to the inlet of said pressure regulating valve, the outlet of said pressure regulating valve communicating with the hot water outlet fitting on said preheater.
 4. A water heater according to claim 2 wherein the slide means comprises a pair of slide runners secured to and extending between the front and rear headers of the boiler, and a pair of guide rails secured to the top wall of the furnace, said guide rails supporting said slide runners. 